The proposed Physician Scientist Award aims to develop in the candidate the capacity for independent investigation directed towards the development of objective measures of performance in everyday physical tasks. The term "objective measures" denotes those measures which do not rely upon judgements either by the individual under study or by an observer, and thus are free from subject or observer bias. These measurement qualities are particularly useful for studies directed towards the growing population of demented elderly with disability, in whom subjective self-reports may be unreliable. Another key advantage of objective measures lies in situations where observers cannot be blinded. Important treatment advances have been made possible by objective measures of ambulation, which are already at an advanced stage. By contrast, there is a great need for valid objective measures of everyday tasks other than walking, such as drinking from a glass or dressing. Such measures will facilitate the assessment of treatments, elucidate the effects of physical and social context upon function, and yield insights into underlying task strategies. However, the development of these measures has been hampered by the complexity of the motions involved. The primary sponsor, a neuroscientist who has worked in the field of motor control for over twenty-five years. The secondary clinical sponsor, is a renowned clinical researcher in functional assessment of the elderly. Both sponsors have extensive experience as research mentors, and have effectively contributed to the academic careers of many young investigators. Consultants include, a pioneer in the field of functional assessment; a measurement expert with a focus on geriatric function; and an authority on the behavioral aspects of movement. Phase I, projected to be two years in duration, will include course work, attendance at seminars and scientific meetings, regular meetings with the secondary clinical sponsor and consultants, and a series of Phase I research projects under the close supervision of the primary sponsor. These projects use structured two-dimensional reaching tasks in order to characterize the strategies by which the nervous system directs movements of the upper limb. The specific aims are 1) to further characterize the intrinsic polar coordinate system through which reaching movements are generated, and 2) to further clarify, through studies in people with sensory stroke, the two roles of sensation in reaching tasks: sensory feedback which allows for adjustments during a movement, and sensory feedforward in which sensory information about the starting position of the limb prior to movement contributes to the motor plan. Phase II, projected to be three years in duration, aims to develop and test one (or several) new objective measures of everyday task performance appropriate for use with elderly persons. The tasks studied will depend upon reaching; thus, the measures developed will exploit the knowledge of reaching strategies developed in Phase I. The measurement development process will begin with structured tasks by normals, and advance towards naturalistic tasks by people with disabilities. This process will also be facilitated by the considerable experience of the secondary clinical sponsor, and consultants, in the development and testing of functional measures in the elderly.